Dental casting-machine.



B. C. MULL.

DENTAL CASTING MACHINE.

APPLICATION mED Aualnmu.

Patented Oct. 17,1916.

2 SHEETS-SHEET l. IGZ@ j B. C. MOLL. oEu'AL CASTING MACHINE.

APPLICATION FILED AUGJS. 19H.

Patented Oct. 17, 1916.

'2 SHEETS-shin 2.

BERNHARD C. HOLL, 0F CHICAGO, ILLINOIS.

DENTAL CASTING-MACHINE.

Specification of Letters Patent.

Patented Oct. i7, 1916.

Application tiled August 2B, 1911. Serial No. 646,413.

To all lli/wm it may concern:

Be it known that l, Brummen C. Mou., a. citizen of the United States of America, und resident of Chica o, Illinois, have invented a certain new an useful Improvement in Dental Casting-Machines, of which the fol lowing is a specification.

My invention relates to dental castm machilies, and more particularly `to a. ental casting machine in which both pressure und vacuum are employed in the casting operation.

One of the objects of my invention is to provide un improved castin machine in which pressure can be applic at the top of the flask and simultaneously the lower part of the flask can be connected with the vacuum chamber.

Another object of my invention is to pro` vide an improved lask which can be readily opened to remove the casting inlay, and which can be fastened together so ns to form an air-tight flask.

A further object is to 1provide suitable adjusting means whereby asks of various sizes can be readily substituted without' interfering with the effective operation of my improved apparatus.

These and other objects of my invention will be more readily understood by having reference to the accompanying drawins, in which similar reference numerals in 'cate like parts, and in which- Figure 1 is a side elevation partl in section of my improved apparatus. Fig. 2 is s plan view of the saine. Figs. 3, 4, 5, 6 and 7 are detail views of various parts of my apparatus. Fig. 8 is a. crosssectional view A of a part of my improved flask.

Having reference to the drawings, I have there shown a. vacuum chamber 10 within which is mounted u suitable pump 1l for creating n vacuum within this chamber in any well known manner. Mounted in one end of this vacuum chamber is a removuble threaded casting 12 within which rests the cone vulve 13 carried by the spindle 14, which spindle is provided with a. laterally extending end 15. This spindle asses throu Y h the elbow of the pipe 16, whic pi exten s horizontally to a point near t e center line of the vacuum chamber, ut which point it turns u wardly and is rovided with a cup-shape bearing 17 within which rests the lower liulf 18 of the flask. The pipe 16 is preferably supported upon the trolling va flat surface 19 of the vacuum chamber, so as to form a more rgid structure. Mounted on the opposite en of the vacuum chamber is a move le standard 20, which is adapted to slide in n suitable guide-way 21 mounted upon the end of the vacuum chamber 10.

1s movement of the standard 20 is accomplished. by means of the rack 22 mounted upon the inside of the standard 20 and the pinion 2 3 which meshes with this rack, which pinion is operated by means of the thumb-nut 24. A locking screw 25 is provided whereby the standard can be held in any desired position Upon the upper end of this stan ard 20 is mounted a yoke 26. Pivotslly mounted within this yoke is a. sleeve 29 which surrounds an arm 27, which arm is provided with an operating handle 28. A. part of this arm is hollow to provide gin air-passage 29 which'arm 27 terminates in e cone-shaped vulve member 30 within thepivotal bearing 31. This cone-shaped vulve is provided with an opening 32 which is adapted to be rotated so as to engage with the passage-way 33 which connects with the air-supply lpipe 34. I have shown a oonve 35 and a. pressure gage 36 connected with this air-supply pipe, whereby I am able to re late the pressure of the air which is supplied to the system. From the construction of this cone valve it will be seen that the valve may be o ned and closed by merely rotating the andle 28, whereby the o 32 can be brought into engagement with the passage-way 33. The oppositeend of this'air-pass e 29 terminates in an angular portion 30* w ich engages with theopening in the top of the cap 38. Extending downwardly from the operating handle there is a rod 37 which is adapted to engage with the laterally extending end 15 of the spindle 14, whereby when the handle 28 is rotated around the longitudinal axis of arm 27 the rod 37 bears against the end of the extension 15, thereby rotating thc spindle 14 so as to operate the cone vulve 13, thereby controlling the connection between the pipe 16 und the vacuum chamber.

The ce. 38, which is adapted to t over the top o the flask, is carried by the sleeve 29. This cap is rovided with an opening which is connect with the air-passage 29, this opening being flared nt its lower portion, and being provided with e perforated pluto to diffuse the nir as it asses through the same. The flask comprises the lower section 18 the upper edge of which section is V-slia cd, while the upper section 1S is provide with u corresponding V-shapcd groove, whereby un air-tight connection is made when these two sections ure brought together. These two sections are held in place by the bolts 39 which pass through the lugs 40 nnd 41 upon the uplper nnd lower sections. By having this llas divided horid zontnlly I am able to obtain ready access to the casting, und it is likewise easier to fill the flask with the investment material. I have shown a blow-pipe 42 pivoted in the yoke member 26 which blow-pipe can be brought into position so as to melt the metal placed in the top of the flask, and can be then swung out of the wey when not in use.

In the operation of my implroved device, the flask is first filled with t e investment material and a wax model absorbed in the usual manner, leaving the mold space with n sp1-ue opening through the top. This mold space is preferably so positioned in the flask that the lower half is in the lower sec tion 18 of the llask, while the upper half is in the u per section. The metal is then placed in t e upper flask above the sprue opening, ns shown, and the blow-pipe then brought into position to melt the metal. The metal having been melted, the blowpipe is then swung out of position and the cap 38 brought down upon the top of the flask by means of the o erating handle 28. When this cap has been rought in position and is fitted securely over t e top of the flask, the handle 28 1s then rotated so as to open communication with the air pressure t rough the passage 29, and with the vacuum chamber through the pipe 16, thus simultaneously causing the pressure and vacuum to act upon the molten metal, and forcing the same through the sprue opening into the mold. It will be seen that in order for the cap 38 to fit securely u on the flask it is necessary that the arm 2 be substantially horizontal when in its lowered posi tion. As the various flasks which may bc employed are of varying height, it therefore becomes necessary to adjust the hei ht oi this arm 27, and this is accomplished y adjustment of the s indle 20 by means of the thumbmut 24, as eretofore described.

l". further advantageous feature of my invention is that the air pressure is not turned .on until after the can has been securely brou lit in place so that there is no dan er of t e air leaking throu h the sides of t e ca due to the fact that t e pressure is turn on before the cup is properly in position upon the flask.

Oertel o! this potent may be obtained for ive While I have illustrated my invention in connection with n combined pressure :ind vacuum system, it is to be understood, of course, that if desired it could bc used with n pressure system nlonc, or with :i vacuum system nlonc, although I find that better rcsults are obtained by the use of the com bined pressure and vacuum. Likewise many other modifications and changes will readily suggest themselves to anyone skilled in the nrt.

What I claim as my invention is:

1. In a dental casting machine, a mold flask, a cap adapted to he swung to and from the top of said flask, an arm carrying said cap, and means for vertically adjusting said arm.

2. In n dental casting machine, a. source of compressed air, and a vacuum chamber, a flask, a cap adapted to be swung to and from said ilask, und means for simultaneously opening communication between said pressure and vacuum chambers after said cap has been brought into position upon said flask.

3. In a dental casting machine, a source of compressed air and a vacuum chamber, a flask, n cap carried by a pivoted arm adapted to be swung to and from said flask, and means controlled by said arm after said cop has been brought into position upon said flask, for simultaneously opening communi cation between said source of compressed air and said vacuum chamber.

4. In a dental casting machine, a vacuum chnmber2 a flask supported upon and having commumcation with said chamber, a standard adjustably mounted upon said chamber, an arm pivotally mounted in the up er end of said standard, and a cup carried lby said arm and adapted to be swung to and from the toIpx of said flask.

5. a dental casting machine, a source of compressed air and a vacuum chamber, n flask supported upon said chamber, ard adjustably mounted upon said chamber, an arm pivotally mounted in the upper end of said standard a and adapted to be swung to end from the top of said flask, and means actuated by said arm when the cap is moved into position on said flask to simultaneously open communi cation between said flask and said source of com rcssed nir and said vacuum chamber.

Signed by me et Chicago, Illinois, this 19t-h day of August 1911.

BERNHARD C. MOLL. l'Vitncsses:

S. Luwls, Gro. SCHMIDT.

cents each, by addressing the "Oommlsaioner at Patenti.

cup carried by Said nrm` a. stand- 

